Flame failure control apparatus



Jan. 27, 1948 c, HAMlLTON 2,434,924

FLAME FAILURE CONTROL APPARATUS Filed June 20, 1945 4 SheetS -Sheet 1 49 ear 47 as ea 36 as 'I'IIIIIIIJII/ 4;"

Jan. 27, 1948.

J. C. HAMILTON FLAME FAILURE CONTROL APPARATUS Filed June 20, 1945 4 Sheets-Sheet 2 .ssa

Jan. 27, 1948. J. c. HAMILTON FLAME FAILURE CONTROL APPARATUS Filed June 20, 1945 4 Sheets-Sheet 3 Ill/II I Jan. 27, 1948. J. c. HAMILTON FLAME FAILURE CONTROL APPARATUS File d June 20, 1945 4 Sheets-$heet 4 1 IE I I Ill-3:5

Patented Jan. 27, 1948 2,434,924 FLAME FAILURE CONTROL APPARATUS James C. Hamilton. Lexington, Mass, assignor to Combustion Control Corporation, Cambridge, Mass, a corporation of Massachusetts Application June 20, 1 945,"Serial No. 600,535

9 Claims. (01. 250-415) This invention relates to electronic control apparatus of the photoelectric type as applied to boilers, furnaces and the like in use in numerous commercial, industrial, marine and other instal-' lations where protection against explosion and other damage caused by flame failure is of Vital importance. More particularly, this invention relates to intermediate mechanical apparatus located between the electronic control apparatus proper and a boiler or furnace interior for the purpose of controllin the light admitted to a photoelectric cell or other light-sensitive member from the flame of the burning fuel and protecting the entire control from heat.

It is a well-known fact that flame failure in oil burners and other types of flame-heated furnaces, boilers and heaters not only disrupts production schedules in industrial plants but often cause very damaging explosions resulting in serious fires and in many instances in heavy loss of life.

One of the chief diiliculties in providing a safety device of the photoelectric type for flameheated furnaces is in obtaining adequate. protec-' tion of the photoelectric cell and other parts comprising the electronic control system against excessive heat.

In the past, due to the fact that light from the flame inside of the furnace must be admitted to the photoelectric cell and that in many furnace installations space is very limited, it has been necessary to mount the photoelectric cell very close to the furnace and to separate the photocell from the rest of the electrical apparatus which .is generally remotely located on a wall of the furnace room. In this case it is usually necessary to connect the photocell to the control apparatus by shielded or coaxial cable.

One of the factors responsible for producing excessive heat is the absorption of infrared radiation by the filter used to prevent this frequency of radiation from reaching the light-sensitive device. This filter is usually composed of a heat-absorbing type of glass. In the past, this filter has been either fixed in a wall of the container enclosing the photoelectric cell or otherwise closely associated with the container in such a manner as to allow considerable conduction of the absorbed heat to the photoelectric cell.

The presentinvention obviates these difiiculties by providing novel intermediate insulating apparatus in combination with the container enclosing the photoelectric cell. Means are provided for removal by convection and radiation not only of conducted heat from the furnace but of the radiatedheat absorbed by the infrared filter and for separation of the filter from the container so that a minimum of heat reaches the photoelectric cell. Because of these improvements it is now possible to enclose the Whole electronic circuit with its component parts in the same container with the photoelectric cell with a resultant shortening of connections between the photoelecfilter is separated from a container in which is tric cell and the rest of the electronic circuit, and elimination of the extra housing and labor of installation. At the same time it is possible to mount the whole apparatus as close to the side wall of the furnace as necessary to permit direct viewing of the flame by the photoelectric ce1l.,

Recapitulating the above features,

The principal object of this invention is to pro-Z. vide an improved apparatus in which is housed-a complete photoelectric flame-failure control system directly connected to the wall of a furnace;

Another object is to provide apparatus of the type above identified in which a heat-absorbing located the photoelectric cell and component parts of the electronic control system;

A still further object in the said apparatus is to provide means connecting said housing with the furnace which permits free circulation of air between the furnace and photoelectric cell container resulting in a substantial lowering of the temperature in said container;

Still another object in said apparatus is to provide for quick and easy cleaning of the several Windows or filters incorporated in said apparatus without the use of tools;

Still further objects in this invention are prejects and novel features will be apparent fromthe following description of the operation and construction.

Referring more in detail to the drawings:-

Fig. 1 is a partial side elevation and verticalcross-section, portions of which are broken off for convenience and other portions of which are shown diagrammatically;

Fig. 2 is a plan view of the principal part of the apparatus. portions of which are broken off for convenience Fig. 3 is a partial vertical cross-section and 3 elevation taken on the line 3--3 of Fig. 2, portions of which are broken away to better show details of the more important elements;

Fig. 4 is an end elevation of the main apparatus as viewed from the furnace end, the pipe member being removed;

Fig. 5 is: a' vertiealicross-sectionstaken .onitliee line 55"'of Fig: 2;one ofthe pivoted elementspf which is shown in its open position, as indicated. H

by the dot-and-dash lines;

line 66 of Fig. 2, one of the pivoted elements of which is shown in its open position. assindicated g -and2=1 and -plate 28; and container body [5 are by the dot-and-dash lines;

after referred to as spacers. The bolts 24 pass through the plates 25, 26, 21 and 28 and the spacers 29 and are tightened up inside of the container body l5 by means of the nuts 30, thereby forming a rigid assembly between the flange 22 and the container body [5. Plates 25, 26, 21 and28'are;each;providd with aacentral orifice 3"lthe edgesofwhich are'rolled'over to form narrow flanges as indicated at 32. The flanges 3| m'of the plates 26 and 2'! face each other while the Fig. 6 is a vertical cross-sectionitakemon-sthee flangexihof ;plate:28 faces the end of the container body l5 which is provided with a bead 33 around the sight l'iole-l8. Between the plates 26 Fig. 7 is a fragmentary cross-sectiorrta'kerr oi'i" '"positioned insulating collars 34, the inside diamthe line 1-1 of Fig. 2 showing themethodofzbolting the various elements of the device together;

Fig. 8 is a fragmentary cross-section taken'on -eterssof; which-.;are greater than the outside diameters of the flanges 32 on the plates and the bead 33 -on the container body I5 50 that at no time can the collars 34 move away from the outside; diameten'ofi'thez-said flanges :31. .PlatexZEis simiiaritorthemtheriplatess26 .25! iand28 "excepting thesorifine 35r whichzisi slightly larger and-rhas nozrolled: edgez: .Ifspreferred; 'therorifice: 35-ofr 1 plate rmay5hethesame asthe orificefilj-in plates.

. 25 Fig: Nis an en'larged fragmentary cross sec tlon" and elevationxportions :ofwhich are broken: away for convenieneey showingthe apparatustas-z used -w-itliout insulating collars betweeni certain: oftl'iewadiati'on platesg and Fig: l l ls 'a partial fragmentary i eross-section and elevation'; portions ofi 'wl iich are ldrolcen aways for convenienceand particularly forshowing a modificatiomof the radiation plates:

Inasmuch -as= thepresent dnven'tiom and' applim cationfis not directly eoncerned witli the -opera tioiroftheelectronin circuit used witlrithephotoelectric cell; the-function of w'l'iich is*well known L'ocated: between plate-z-i25a and: plate: 26 zis aw shutter. :member :36: .Iihis shutter-636 is provided in=tlie"-art; detailed description will be limited toi- 1 with:aihoss: 31 see Fig: 13'; which'gis: journalled-at 3-8r amundnneiofrtheztop spacersiai "011T therlower-- emtofishutterrfia'proiectsianrextensionifingerswi for the purpose of providingva finger grip-for,

.tlie operaton'tto:swingdaheeshutteitontwardly1mm thezplates' 25fand261. nifrictionispringsclipzfiflsisr attachedeto:theinsidaface tof:theaextension finger: 392' When: the TShXlttGI'TiS-Z closedzthez clip" 40?; em gages? over'the-a-spacers' fl; as: shovim-in'li'igs :5,

: normally holding": said shutter: incaixclosedrrpositioniz "Iihe: shutter 35r.="is:1alsoxprovided with: an

orificezas indicated: at 41*- wliichzis in 1axial'1alignmenttanduconcentrici relationship witharespect :to the: openingsz'in ith'e pipeeboss rofiflange 22, plates 7 25'; '26, J21;28r andfsightsopeningaltfl im the con-- movable=cover=which may beattached tothecontainer'inan -air--tig-ht="manner use of ausuit' able gasket if desiredi Within the-containerib'ody 5 is located a conventional pliotoelectric -cell [1; the cathodeelement 'ot which is "exposed'to a; sight opening I 8 provided in theiront end of the containerbody' IS. A- piece of plaiir' glass or=other transparent medium" Hl ifssealed-=in* a- =moist-ureproof 'manner'in'- a recess=located ontlieinside of the-container-bodyi 5 around the s'ig ht opening 1-8; Any con-venient *fastening means for securing *the' transparent-"member" I9 as'tlie-iasteners 20 and screws 21 may be' used;

At 22-is-located =a-pipe flitnge= wliichis provided with bosses 2 3 located at 'its four cornerst The. bosses 23 are counterbored' to receive the'=s0cket heads-of bolts 24, the threaded ends ofwhichpass througlialiol'es r-in tl'ie container body IS and terminate' insider-of said container-: "If preferred, the threaded ends of bolts 24 mayibe=securedin= threaded bosses located on the exterion-of the tionsl'iip between the flange 22 -and the container body I5 by means of spacing sleeves 29 hereintainer body l5. On the side of theshutter iifi facing: the containerribodyr'l Erwisslocated: a vrecess 42'i-also concentrically locatediwith .IBSPBCt'LtO th? orifices'in'ithe other members irrw-hiclr isrfastened; byrmeansiof fa .snaptringr43 a plain' heat-resistant sight glass :orrother transparent':medium-44: 6n the si'de 10f? the'slmtter: 36i adjacentfithe plate 25 are'located two rivet fmembers 45;-the flat heads. of; which bear againstrzthe ssiderof the plate: 2 5"; andmaintain' th'e shutter raway: fT'Om'Dm-k side otfthe plate253 tas=shown 3. An airspace l ifiz is thus DIOVidBdibEtWBEHithE plateflfipanct shutter 36? the reason for which wwi'llzbmexplained :further alongrimthe:descriptiom:

'BetweemtheplatesvZ-l and-3 28 7 isslbcated a'ssec ond 'shutter'v 41; r This; shutter- =isz identica-l '"with: shutter==3fiawith .oneeexceptiom "the; rivets '45?- of shutter-26mm eliminated; A-. clip' member Add attached to the flnger 39diz'iSiP1OVid8d as-in shutter 36 andf engages'roverfiaz correspondingrspacer' 292 rin order tozzprovi'de'aazzclosea contact of-rthe: shutter d! withithe'platesrfliarrdk2fij thesspacers- 29 in this section are ysiightly'shorterr than: those; in the' 'section' ocoupiediby the shutter*36-tovthe extent sof' the :approximateswidth of: the airspace 46 workingrtolerances:excepted': .Asanoted in the drawings; shutter i r'is mountedqirx aniopposite mannerzto sl'mtterf36so' thattitiswings-outwardly fromzthemtherzsidenf therassemblyr -Iaocatediincthea-recess-Hm oi-shutter fl l isran. infrared filter member 48 held in place by another 49 may bewelded or'connected'byotherfmeans to-' the furnace wall in WhiC'IYQ. HGIe'oF'su'itablesize has beencut: "'Tl'ief'pipe'i's attached to the fum'a'ce' wa'l'l'"in.'-such 'a' position tha'ifits *axispasses out ob'struc'tion throug'htsome part, pre'ferabiy'the hottest part-ofthe 'flam'ei'l ifrox'i By an inspection of Figs. 1'and3'.'itw llbenoted that" the horizontal axes" of the openings 'ofthe. pipe "49; "flange 22; platestfiiiflii .215 "zfian'd sight" opening-t8inth-e"containerbody:li'wcoh'mlde;so that light from the flame'dsadmitteiit'o'fthecatm ode of the'photoe'lectriccell'illf "Failure the flame 51 withtheresultantiihangeinthelightfall ingontherphotocell wilfimm'ediatlyi cause'el'e'c 1' trical changesfin' the electrorfivdiicuftsdesigned tocontrorfuelfe'edimestotheburner 'suchelec: tronic control meansbeing :we'fl "knownmthe art'. In operatiomthe shntters"36"aniffl are"closed; ass'how'n "iriIFlg; '3' df'the drawmgs'? Intli'e'closed position .of'shutter 36""it'Wil1ibemoted that between-the pl'ate fiand'the 'shuttertherefis""pres=' ent air spaceipreviouslyreferred to'arrd indicatedbythe numeral '16; lt'will be .notediby an inspection 'ioffFig. 3* 'that this :air space 46' is positionedl'onthe fireboxfs'id'e of the transparent member 4'4. Since;:.in-.:most furnaces, the .plES sure 'insidethe firebox is 'somewhatil'ower than. atmospheric ,pressure because. of ftl'ie. lchimhey draft, a smallialnount .of'lair. wilThEfldiaWn into the pipe, #91 -'In the presentiid'evic'e .the current: of air through the space 4'6 tends to coolthe memberandalso. reduces .to. a -minimum the deposit off'soo'tion the membersoftha'tthe neces sity for irequentw cleaning, with. the. attendant. possibility of breakage; is elimiii'alted; .Wh'enk ever .it becomes necessary. to. clean; the transparen'tmemberlM; thelshutterliil'i Jnaylbe swung by. useoithe -finger Y39-Iand .hdthr-sidesof the member .44' may ;be wiped. off. clean. .When the shutterfisagainclosed, the spring cliplmengages; over thelspacer 19,. ilioldingu'the. shutter securely inplace asshowninifiigfi. In .asimilar. mannenthe shutter: A] carrying. the 'ihfraredfilter 'd'fllm'aiy benswungroutzandfithe filter"; cleaned; of any...-diist.i particles which .may. have collected on it.. L'I!he..arrangement .of.the shutters on oppositesides-iof the apparatus makes the possibility of their both being opened simultaneously unlikely sorthatthe"chance of a momentary. blow-back of the furnace causingma deposit ofsoot on glassl*9 is'extremelyTemote; As heretofore mentioned in"the"'dbjective's of this invention; due to the noveluconstruction of this apparatus the infrared filter is mountedmnt sideflf. the casing enclosing- Zthe photoelectric cell and electricalcircuits, etcaand such-atilter may, it desired," be space'dLst'flh-further'.away from said-".casingbythe simple expedientsofaadde ing .moreplat'e's' and-spacers between plate 128 and the casing. In some 'ins'tallat'idns'l the temperature? ofJthe boiler wall m'ay..'he very high-and additional plates and spacers-may alsowbe requ'ired' between the 'ii'lter' and the mounting flange. Where it is desired to*'ad'd more plates either :betweenr plates- 26-andi2i| .or-xplaite wzand casing l5 zinoz' fin' zcnn'strnctiomisi nBoEs-e sary except for the use of correspondingly longer heatacquired 1 by these plates by conduction through-"tire-h'rounfing flange frorn' rthef-urnace. wa-ll and by contact w-i-tli the heat absorbi-ng" enema.

"The insul'atin co'llars" 3i -are=- mainlyprewit'ied forwise'iunder very dusty conditions for the pur pose'-of-"reduci-n dust'accumulationpn the trans parentm'embers"*M ahd- 48; h'oweveryunder ex tropical climates: the collars -34 rrfay bedispensed thereby reducing the '=possibi1ity-- of moisture condensation orr'the transparent *members when the furnace-is not in use;

As previously set' forth; the I present invention may 'be applied to'marine "installations and other provide-aga'ihst=*premature or accidental opening ofitheshuttersfifi and M? a locking'memb'erhas beenprovided as shown "in: "the fragmentary cross-sections shown in *Figsi 8 and 9; Referring more in detaihtoFig. 8 ifwi'll he notedtha'tjthe flange 22 has been provided-with :extension portion b'll', the innersurface'of wliidhis counterbored 6 i threaded; at"62 the threaded.

portion"62 ib'eing'sl'ightlysmaller in" diameter:

The shutterfiliis'provided Withathread'ed hole 63 fata point in axial alignment 'with'fthe' threaded openingf6'2 "on the Lfiange 22 when the shutter screw comprising'za knurled extension end 64, shank F5; and" enlarged threaded plug. end '66.

When'it is des'ired t'o lock the shutter36inplace, the plug, end"6'6"niay be; threaded. through the hole" 62 Land "then i pushed through .counterbored recesslfil "and'anjen'larged hoI'eG'l located in plate 25; after which Ithe"plugjlifijis'fthreaded' into the hole.'63"inltlie shutter -361andt'ightened up. against the 'fiangeil'i To open the shutter "36, the .plugffili of'ithe captivescrew is unscrewed fromthe -threa'cled hole 631in'ftheshutter anfdfwithdr'a'wn into the 0011111 terbored areaffil vof'the' flange-22 land the; shutter. 36" may beswung out .as. previously described.

66}. captive screw will not fall out and reduiresjfur'ther unscrewing to removejitifrom the.

assembly, 1 thereby l lteven'ting 1 s. or. mislaying of. said. screw.

"m a similar.manner,,,.a captivelscrewlniaybe. providedionifthe other s'ideJof the. apparatus to. lo clln'theshutter filasishown in-.F.'ig..9.. Eor the; sake of -simplicity,...similar numerals, as. 60a tofilza, .have been used .inuFig. .9. thev locking: and unlocking action fleeingddentical-ein either instance; tITl: stationary'installationswhere "the :appa-- natus- .isvn-ot "-likelyto *besubjected to. sudden:

shocks, etc., the captive screws may be removed.-

entirelyror ztheyimayilbe ileftiin -zan unlockedfiposltionzassxlesired: 7'1

'smscmntlerricertaimconditicns wheretit fisxnuti er temperature than"the surrounding air arrd the tact thalt' open spacingts present'between the plates; there is aninduced circulation :of air up through these openings resulting in eflicient removal of the desirable to admit any air to the furnace except through the burner, the rivets 45 in the shutter 36 may be eliminated so that the shutter andplate 25 efiect a seal when the shutter is closed similar to shutter 41 and plates 21 and 28, better shown in Fig. 10.

The apparatus disclosed in Fig. 10, in which the insulating members 34 have been removed, will function properly under all normal conditions. To further prevent any outside rays of light from reaching the sight opening, H3 in the container I5, as might happen under abnormal;

viding a continuous passage for induced air cur-' rents up through the apparatus and across the transparent members-44 and 431. This type of construction is desirable in some marine installations. r

While the above description has dealt with the invention in specific connection with flame failure in furnaces and the like, it is to be understood that it may equally apply to other uses of a similar nature such as smoke control, densitometersor other apparatus in which lightsensitive equipment is used, within wide limits within the spirit of the appended claims.

Having thus described the present invention, what is claimed as new is l. A light-restricting container for housing a light-sensitive member comprising, heat-radiation members spaced apart and away from said container, supporting means for said container, means for circulating air between said radiation members and a heat-absorbing filter mounted between and in close proximity to said radiation members. I

2. A light-restricting container for housing a light-sensitive member comprising, heat-radiation members spaced apart and away from said container, supporting means for said container, means for circulating air between said radiation members, a heat-absorbing filter mounted between and inclose proximity to said radiation members, a transparent member located between said radiation members, and means for admitting a controlled amount of air across one side of said transparent member.

3. A housing apparatus comprising, a container housing a light-sensitive member, a sight opening located in one side of said container adjacent said light-sensitive member, heat-radiating plates spaced apart and away from said container and having apertures aligned with said sight opening, supporting means for said container, a shutter memberpivoted on said supporting means between a pair of said heat-radiating plates, a heatabsorbing filter mounted in said shutter and normally aligned with said apertures, a second shutter member pivoted on said supporting means between a second pair of said heat-radiating plates, a transparent membermounted in said second shutter and normally aligned with said apertures, and an air inlet provided on one side of said second shutter for the purpose of allowing air to flow across one side of said transparent member.

4. A housing apparatus comprising a container housing a light-sensitive member, a sight opening located -int'one side of said container. adjacent said light-sensitive member, heat-radiatingplates. spaced apart and away from said container and having apertures aligned with said sight opening, supporting means for said container, a shutter member pivoted on said supporting means becaptive in oneof said plates and threadably en-.

gaged with said shutters.

6. Housing apparatus for a light-sensitive device comprising, a closed container having a sight opening adjacent saiddevice; a plurality of plates having apertures aligned with said sight opening;

a pipe flange coaxially aligned with. said aper-- tures; a plurality of bolts connecting saidflange and said plates to said container; spacers encircling said bolts for spacing said plates apart and away from said container; a shutter. pivoted.

on one of said bolts between-one pair of said plates and having an opening,.normally aligned with said apertures, wherein is mounted a heat-absorbing filter; and asecond shutter, pivoted on one of said bolts between a second pair of said, plates, and having an opening, normally aligned with said apertures, wherein is mounteda transparent member.

'7. Apparatus in accordance with claim 6 wherein said sight opening and said apertures are surrounded by lips having insulating collars mounted thereon.

8. Apparatus in accordance with claim 6 wherein said sight opening and said apertures are surrounded by lips overlapping but spaced away from each, other.

' 9. Housing apparatus for a light-sensitive device comprising a closedcontainer having a sight opening adjacent said device; a heat radiating plate having an aperture, aligned with said opening; a pipe flangecoaxially aligned with said aperture; a plurality of bolts connecting said flange and said plate to said container: spacers encircling said bolts for spacing said plate away from said container; ashutter pivoted on one of said bolts and a heat-absorbing filter mounted in.

close proximity to said plate.

JAMES C. HAMILTON.

REFERENCES one!) The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,033,857 Smith et al Mar. 10, 1936 1,973,468 Denis Sept. 11, 1934 2,243,048 Foster et al. .May 20, 1941- 2,122,941 Hufler et al. July 5, 1938- 1,853,444 McCabe -Apr. 12,1932- 1,945,652 Martin Feb. 6, 1934 2,054,382 Larsen et al Sept. 15, 1936 1,745,178 McCabe Jan. 28, 1930 OTHER REFERENCES Bailey Flame Detector Publication. pages 3-6, Nov. 8, 1939. Copy in Div. 19, 158-29(F). 

